It is strange that “senile pigment freckle” has attracted little attention to the Japanese, European and American dermatologists although this skin disorder is frequently seen on the exposed areas of almost all aged persons. We examined biopsy specimens of these “senile pigment freckle” and observed that they showed characteristic morphorogical changes of three types.
1) Hyperpigmentation type:
The main histological finding is the hyperpigmentation of the basal layer in the epidermis.
2) Lentigo type:
The most characteristic features are that small clup-shaped project of epidermal cells into the dermis and many melanocytes and melanin pigments in the basal layer of epidermal club-like projection are seen.
3) Pigment incontinentia type:
In this type It is noticed that little pigments in the epidermis and many macrophages in the upper part of dermis are observed. This pigment incontinentia type of “senile pigment freckle” is tne histological form that we newly found. Cliniealy, these lesions must be diffrentiated from ephehdes, junctional nevi, seborrheic keratosis, and Dubreuilh’s precancerous melanosis. It is considered that chronic actinic exposure may play a leading role in the pathogenesis of “senile pigment freckle”.
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